Paper Feeding Device

ABSTRACT

A paper feeding device comprises a cover, a roller frame and at least one paper blocking unit. The roller frame has two side walls. The paper blocking unit is placed beside the side wall, having a projection mounted on the side wall of the roller frame and a paper blocking element including a connecting portion, the connecting portion has a positioning pillar rotatablely connected to the cover. The connecting portion extends downwards to form a stopping portion, the stopping portion further extends downwards to form a paper blocking arm, the lower portion of the paper blocking arm defines an opening communicating one side of the paper blocking arm near the side wall. The projection can stops at the stopping portion and passes through the opening of the paper blocking element to allow the document to be fed in, so the cooperation is easy, the paper feeding device works smoothly.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a paper feeding device, and moreparticularly to a paper feeding device having paper blocking unitapplied in an office business machine.

2. The Related Art

Recent business machines, such as a scanner, a printer, a copier, etc.,are broadly required in the office operation. The business machine has afunction of image disposing. Take a conventional scanner as an example,an image disposing system of the scanner includes a glass plate, anoptical system arranged under the glass plate for reading the image ofthe document placed on the glass plate. As a result of the applicationof the ADF (automatic document feeder), a stack of documents are placein a document tray of the ADF, then the documents are fed into thescanner one by one and placed on the glass plate by a paper feedingdevice of the ADF, at last, the optical system reads the image of thedocument.

In the conventional scanner, the paper feeding device further comprisesa paper blocking unit, which is used to make sure that the document isplaced in a proper position before being picked by the paper feedingdevice, thereby, the document is picked by a picking roller of the paperfeeding device.

Please refer to FIGS. 1-2, a conventional paper feeding device havingpaper blocking unit 1′ includes a conveying roller 10′, a picking roller20′, a blocking unit 30′ and a blocking arm 40′. The conveying roller10′ and the picking roller 20′ are parallel to each other and located ina roller frame 50′, the blocking unit 30′ sleeves on the shaft of thepicking roller 20′. The blocking arm 40′ is located on the roller frame50′. Before the document being picked, a blocking projection 41′ of theblocking arm 40′ leans against a stopping projection 31′ of the blockingunit 30′, the documents 2′ are stopped outside, the picking roller 10′keeps a certain distance from the documents 2′. Then referring to FIG.2, when the document 2′ is to be picked, the roller frame 50′ drives thepicking roller 10′ to move downwards, the blocking arm 40′ rotates andthe blocking projection 41′ impels the stopping projection 31′ of theblocking unit 30′ to move upwards, as a result, the blocking arm 40′loses the cooperation with the blocking unit 30′, then the documents 2′are not stopped by the blocking arm 40′, at the same time, the pickingroller 10′ contacts with the documents 2′ and the document 2 s′ are fedinto the scanner one by one via the paper feeding device 1′.

As described above, the blocking projection 41′ impels the stoppingprojection 31′ of the blocking unit 30′ to move upwards, thereby, theblocking arm 40′ loses the cooperation with the blocking unit 30′, thenthe documents 2′ are not stopped by the blocking arm 40′ and fed intothe scanner one by one. However, the cooperation between the blockingarm 40′ and the blocking unit 30′ is liable to be lost, then theblocking projection 41′ isn't able to impel the stopping projection 31′to move, consequently, the document 2′ isn't able to be fed into thepaper feeding device 1′, the paper feeding device 1′ can not worksmoothly.

SUMMARY OF THE INVENTION

Accordingly, an object of the present invention is to provide a paperfeeding device, comprising a cover, a pickup roller assembly and atleast one paper blocking unit. The retaining portions are mounted on aninner surface of the cover. The pickup roller assembly picks up and thentransfers papers into the paper feeding device. The paper blocking unitis placed beside the pickup roller assembly, having a paper blockingelement and a projection mounted on the pickup roller assembly. Thepaper blocking element includes a connecting portion, the connectingportion has a positioning pillar rotatablely connected to the retainingportion of the cover, the connecting portion extends downwards to form astopping portion, the stopping portion extends downwards to form a paperblocking arm, the paper blocking arm defines an opening communicatingone side of the paper blocking arm near the pickup roller assembly. Theprojection can stops at the stopping portion of the paper blocking armand passes through the opening of the paper blocking arm.

As described above, the paper feeding device stops the documents by thecooperation between the paper blocking element and the projection, whento feed documents, the projection passes through the opening of theblocking element to allow the document to be fed in, so the cooperationis easy, the paper feeding device works successfully.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be apparent to those skilled in the art byreading the following description of a preferred embodiment thereof,with reference to the attached drawings, in which:

FIGS. 1-2 show a conventional paper feeding device;

FIG. 3 is an exploded perspective view of a paper feeding device havingpaper blocking unit of the present invention;

FIG. 4 is a partial enlarged view of the encircled portion labeled IVshown in FIG. 3;

FIG. 5 is a perspective view of a pickup roller assembly;

FIG. 6 is a perspective view of a paper blocking element shown in FIG.3; and

FIGS. 7-9 are side cross-sectional views for describing operations ofthe paper feeding device of the present invention.

Please refer to FIG. 3, the paper feeding device of the presentinvention includes a cover 10, a pickup roller assembly 20, a base 40and a paper blocking unit 30.

Then please refer to FIG. 4 in combination with FIG. 3, a pair ofplate-shaped retaining portion 11 projecting from the inner surface ofthe cover 10 and are parallel to each other, a restricting projection 12is formed therebetween, a retaining hole 111 is opened in the retainingportion 11. Below the retaining portion 11, a pair of connectingportions 13 is mounted on the inner surface of the cover 10, and areceiving space 14 is formed therebetween.

Referring to FIG. 5, the pickup roller assembly 20 includes a rollerframe 21, a belt 22, a picking roller 23 and a conveying roller 24. Theroller frame 21 has a left side wall 211 and a right side wall 212, anactive shaft 214 and an idle shaft 213 are parallel located between theleft side wall 211 and the right side wall 212, a conveying roller 24 ismounted around the active shaft 214 and a picking roller 23 is mountedaround the idle shaft 213. A belt 22 is sleeved on both the conveyingroller 24 and the picking roller 23, and impels the conveying roller 24and the picking roller 23 to press against the roller frame 21.

Please refer to FIG. 3 and FIG. 6, the paper blocking unit 30 includes apaper blocking element 31 and a projection 32. The paper blockingelement 31 has a connecting portion 311, two opposite sides of theconnecting portion 311 project to form a positioning pillar 312respectively. A front end of the connecting portion 311 extends upwardto form a restricting arm 313, the restricting arm 313 leans against therestricting projection 12 of the cover 10. The back end of theconnecting portion 311 extends downwards and forms a stopping portion315, the stopping portion 315 further extends downwards to form a paperblocking arm 314, the lower portion of the paper blocking arm 314defines an opening 316 communicating the bottom and the right side ofthe paper blocking arm 314. The projection 32 is mounted on the leftside wall 211 of the pickup roller assembly 20.

Please refer to FIGS. 3-6, the assemblage of the paper feeding device 1of the present invention is described in detail hereinafter. Firstly,the belt 22 is sleeved on both the picking roller 23 and the conveyingroller 24, the active shaft 214 and the idle shaft 213 are located inthe roller frame 21 between the left side wall 211 and the right sidewall 212, the pickup roller assembly 20 is assembled. Then the activeshaft 214 is rotatablely connected to the connecting portion 13 of thecover 10 and the pickup roller assembly 20 is received in the receivingspace 14 therein. Secondly, the paper blocking unit 30 is placed besidethe pickup roller assembly 20, in this embodiment, the paper blockingunit 30 is placed at the left side of the pickup roller assembly 20, thepositioning pillar 312 of the paper blocking element 31 is rotatablelyconnected to the retaining hole 111 of the cover 10, the projection 32stops at the stopping portion 315 of the paper blocking element 31.Lastly, the cover 10 covers on the base 40, then the paper feedingdevice 1 of the present invention is assembled.

As shown in FIG. 7, when the paper feeding device 1 is in natural state,the picking roller 23 keeps a certain distance from the document 2, thedocuments 2 are stopped outside by the paper blocking arm 314, theprojection 32 stops at the stopping portion 315 of the paper blockingelement 31, the restricting arm 313 is stopped at the restrictingprojection 12.

Please refer to FIGS. 8-9, when the paper feeding device 1 picks up thedocument 2, a motor (not shown) drives the active shaft 214 to rotateclockwise, so the conveying roller 24 mounted on the active shaft 214rotates, a friction created between the conveying roller 24 and the belt22 drives the belt 22 to move along with the conveying roller 24, then afriction created between the belt 22 and the picking roller 23 drivesthe picking roller 23 to rotate clockwise. As the picking roller 23 andthe conveying roller 24 both press against the roller frame 21, when thepicking roller 23 and the conveying roller 24 rotate clockwise, afriction created between them and the roller frame 21 drives the pickuproller assembly 20 to rotate clockwise around the active shaft 214, thenthe picking roller 23 contacts with the document 2. Meanwhile, as thepickup roller assembly 20 moves downwards, the projection 32 mounted onthe left side wall 211 of the roller frame 21 also moves downwards andpasses through the opening 316 of the paper blocking element 31, so theprojection 32 loses the cooperation with the stopping portion 315 of thepaper blocking arm 314, the blocking arm 314 rotates clockwise aroundthe positioning pillar 312 and is no longer stop the documents 2. Thenas the belt 22 contacts with the document 2 and rotates clockwise, thefriction created therebetween picked the document 2 into the paperfeeding device 1.

On the contrary, when the paper feeding device 1 stops to pick documents2, the motor (not shown) instantly rotates reversely and thereforedrives the active shaft 214 to rotate anti-clockwise, then the conveyingroller 24 and the picking roller 23 both rotate anti-clockwise. As thepicking roller 23 and the conveying roller 24 both press against theroller frame 21, then a friction created between them and the rollerframe 21 drives the pickup roller assembly 20 to rotate anti-clockwisearound the active shaft 214 and move upwards, so the picking roller 23departs from the documents 2, the paper blocking arm 314 rotatesanti-clockwise around the positioning pillar 312 under its own weight,meanwhile, the projection 32 mounted on the roller frame 21 passesthrough the opening 316 (shown in FIG. 6) of the paper blocking arm 314and stops at the stopping portion 315, the restricting arm 313 stops atthe restricting projection 12 of the roller frame 21, then the pickingroller 23 and the conveying roller 24 stop to rotate, as shown in FIG.8, the paper feeding device 1 is in natural state, the documents 2 arestopped outside by the paper blocking arm 314.

As described above, the paper feeding device 1 stops the documents 2 bythe cooperation between the paper blocking element 31 and the projection32, when to feed documents 2, the projection 32 passes through theopening 316 of the blocking element 31 to allow the document 2 to be fedin, so the cooperation is easy, the paper feeding device 1 workssmoothly.

The foregoing description of the present invention has been presentedfor purposes of illustration and description. It is not intended to beexhaustive or to limit the invention to the precise form disclosed, andobviously many modifications and variations are possible in light of theabove teaching. Such modifications and variations that may be apparentto those skilled in the art are intended to be included within the scopeof this invention as defined by the accompanying claims.

1. A paper feeding device, comprising: a cover, a pair of retainingportions mounted on an inner surface of the cover; a pickup rollerassembly picking up and then transferring papers into the paper feedingdevice; at least one paper blocking unit placed beside the pickup rollerassembly, having a paper blocking element including a connectingportion, the connecting portion having a positioning pillar rotatablelyconnected to the retaining portion of the cover, the connecting portionextending downwards to form a stopping portion, the stopping portionextending downwards to form a paper blocking arm, the paper blocking armdefining an opening communicating one side of the paper blocking armnear the pickup roller assembly; and a projection mounted on the pickuproller assembly, wherein the projection can stops at the stoppingportion of the paper blocking arm and passes through the opening of thepaper blocking arm.
 2. The paper feeding device as claimed in claim 1,wherein a retaining hole is opened in the retaining portion of thecover, the positioning pillar of the paper blocking element is connectedto the retaining hole.
 3. The paper feeding device as claimed in claim1, further comprising a picking roller and a conveying roller locatedbetween the two side walls of the roller frame.
 4. The paper feedingdevice as claimed in claim 3, wherein the conveying roller is mountedaround an active shaft, the active shaft passes through the two sidewalls of the roller frame.
 5. The paper feeding device as claimed inclaim 4, wherein a pair of connecting portions are mounted on the innersurface of the cover below the retaining portion, and a receiving spaceis formed between the two connecting portions for receiving the rollerframe with the two ends of the active shaft connected to the connectingportions.